readencryptedmail.java

用java实现的对电子邮件进行加密解密及签名的算法接口

package cn.edu.scut.smimeapi;

import java.io.*;
import java.security.*;
import java.security.cert.*;
import java.util.*;

import javax.mail.internet.*;
import javax.mail.Multipart;
import org.bouncycastle.cms.RecipientId;
import org.bouncycastle.cms.RecipientInformation;
import org.bouncycastle.cms.RecipientInformationStore;
import org.bouncycastle.mail.smime.SMIMEEnveloped;
import org.bouncycastle.mail.smime.SMIMEUtil;
import javax.mail.Message;
import cn.edu.scut.certmgr.*;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import java.security.PrivateKey;



/**
 * a  class that reads an encrypted email.
 */
public class ReadEncryptedMail extends ReceiveMail
{

 /**
            * Return a String Cert alias which is to be used to get private key .
            *
            * @param KeyStoreManager ksm the keyStrore object to manager the key.
            * @param RecipientId  rid the RecipientId which is relate to the receiver  .
            * @throws Exception
*/
 public String GetCertaliasByRId(KeyStoreManager ksm,RecipientId rid) throws
     KeyStoreException,IOException
 {
    String Certalias=null;
    try
    {
        KeyStoreCertificates ksc = ksm.getAllCertificates();

        for(int i=0;i<ksc.itemCount();i++)
       {
            if(ksc.getCertItem(i).hasPrivateKey())
           {
               String alias = ksc.getCertItem(i).getAlias();
               X509Certificate cert =(X509Certificate) ksm.getCertificate(alias);

               if (cert instanceof X509Certificate)
               {
                 if (Arrays.equals(cert.getIssuerX500Principal().getEncoded(),rid.getIssuerAsBytes()))
                 {

                   if(cert.getSerialNumber().equals(rid.getSerialNumber()))
                   {
                             Certalias=alias;
                   }

                 }
               }

           }

       }

    }
    catch (KeyStoreException ek)
    {
     throw new KeyStoreException("KeyStoreException:"+ek);

    }
    catch (IOException ioe)
    {
      throw new IOException("IOException:"+ioe);
    }

    return Certalias;

 }

 /**
  * Return a MimeBodyPart which has been descrpted  from the EncryptedMsg by usb token .
  *
  * @param MimeMessage EncryptedMsg,  the message which has been  Encrypted.
  * @param char[] userpin the password which is relate to usb token  .
  * @throws Exception
*/

public MimeBodyPart ReadEncryptedMailAutoByToken(MimeMessage EncryptedMsg,char[] userpin)
     throws Exception
 {
   if (!EncryptedMsg.isMimeType("application/pkcs7-mime"))
   { //非加密邮件
     throw new Exception("It is not a Encrypted message!");

   }

    MimeBodyPart res=null;    //解密后的邮件正文
    ProviderConfiguration pConfig = new ProviderConfiguration("Config.xml");

    //============= Get private key from epass2000 USB token
    ConfigFileItem configItem = pConfig.getConfigItem(1);
    KeyStoreManager ksMgr = new KeyStoreManager(configItem, userpin);//密码

    SMIMEEnveloped m = new SMIMEEnveloped( (MimeMessage) EncryptedMsg);
    RecipientInformationStore recipients = m.getRecipientInfos();
    Collection                c= recipients.getRecipients();
    Iterator                it = c.iterator();

       //
       // check each recipient
       //
      String Certalias=null;
       while (it.hasNext())
       {
          RecipientInformation recipient = (RecipientInformation)it.next();
          RecipientId           recId    =recipient.getRID();
          try
          {
            Certalias                      =GetCertaliasByRId(ksMgr,recId);
          }
          catch(KeyStoreException ex4)
          {
            System.err.println("Get Cert's alias error:"+ex4);
            throw new KeyStoreException(ex4);
          }

          try
          {
          TokenPrivateKey tpk=ksMgr.getTokenKey(Certalias,null);
          res = SMIMEUtil.toMimeBodyPart(recipient.getContentByToken(tpk.getPrivateKey(),
       tpk.getProvider()));
          }

         catch (Exception ex3)
         {
           System.err.println("Decrypetd the mail error:"+ex3);
           continue;
         }
      }

    if (res==null)
    {
    throw new NullPointerException("the mail not decypted success!");
    }

   return res;
 }

 /**
  * Return a MimeBodyPart which has been descrpted  from the EncryptedMsg by LocalKey .
  *
  * @param MimeMessage EncryptedMsg,  the message which has been  Encrypted.
  * @param char[] userpin the password which is relate to LocalKeyStore  .
  * @throws Exception
*/
 public MimeBodyPart ReadEncryptedMailAutoByLocalKey(MimeMessage EncryptedMsg,char[] userpin)
      throws Exception
  {
    if (!EncryptedMsg.isMimeType("application/pkcs7-mime"))
    { //非加密邮件
      throw new Exception("It is not a Encrypted message!");

    }

     MimeBodyPart res=null;    //解密后的邮件正文
     ProviderConfiguration pConfig = new ProviderConfiguration("Config.xml");

     //============= Get private key from LocalKeyStore
     ConfigFileItem configItem = pConfig.getConfigItem(0);
     KeyStoreManager ksMgr = new KeyStoreManager(configItem, userpin);//密码

     SMIMEEnveloped m = new SMIMEEnveloped( (MimeMessage) EncryptedMsg);
     RecipientInformationStore recipients = m.getRecipientInfos();
     Collection                c= recipients.getRecipients();
     Iterator                it = c.iterator();

        //
        // check each recipient
        //
       String Certalias=null;
        while (it.hasNext())
        {
           RecipientInformation recipient = (RecipientInformation)it.next();
           RecipientId           recId    =recipient.getRID();
           try
           {
             Certalias                      =GetCertaliasByRId(ksMgr,recId);
           }
           catch(KeyStoreException ex4)
           {
             System.err.println("Get Cert's alias error:"+ex4);
           }

           try
           {
           Key pkey=ksMgr.getKey(Certalias,userpin);
           res = SMIMEUtil.toMimeBodyPart(recipient.getContent(pkey,"BC"));
           }

          catch (Exception ex3)
          {
            System.err.println("Decrypetd the mail error:"+ex3);
            continue;
          }
       }

     if (res==null)
     {
     throw new NullPointerException("the mail not decypted success!");
     }

    return res;
 }

 /**
  * Return a MimeBodyPart which has been descrpted  from the EncryptedMsg by Localkey .
  *
  * @param MimeMessage EncryptedMsg,  the message which has been  Encrypted.
  * @param PrivateKey privatekey, the key which is to be used to descrpted the msg.
  * @param X509Certificate cert the certificate  to generate a suitable recipient identifier
  * @throws Exception
*/
public MimeBodyPart ReadEncryptedMailByLocalkey
         (MimeMessage EncryptedMsg,PrivateKey privatekey,X509Certificate cert)
      throws Exception
  {
    // use the certificate  to generate a
    // suitable recipient identifier

    RecipientId recId = new RecipientId();

    recId.setSerialNumber(cert.getSerialNumber());
    recId.setIssuer(cert.getIssuerX500Principal().getEncoded());
    // handle with message
    if (!EncryptedMsg.isMimeType("application/pkcs7-mime"))
    { //非加密邮件
      throw new Exception("It is not a Encrypte message!");

    }

    SMIMEEnveloped m = new SMIMEEnveloped( (MimeMessage) EncryptedMsg);

    RecipientInformationStore recipients = m.getRecipientInfos();
    RecipientInformation recipient = recipients.get(recId);


    MimeBodyPart res = SMIMEUtil.toMimeBodyPart(recipient.getContent(privatekey,
        "BC"));

    if (res==null)
     {
     throw new NullPointerException("the mail not decypted success!");
     }

    return res;

  }
  /**
   * Return a MimeBodyPart which has been descrpted  from the EncryptedMsg by USB_Token .
   *
   * @param MimeMessage EncryptedMsg,  the message which has been  Encrypted.
   * @param TokenPrivateKey TokenKey, the key which is to be used to descrpted the msg.
   * @param X509Certificate cert, the certificate  to generate a suitable recipient identifier
   * @throws Exception
*/
  public MimeBodyPart ReadEncryptedMailByToken
         (MimeMessage EncryptedMsg,TokenPrivateKey TokenKey,X509Certificate cert)
       throws Exception
   {
     // use the certificate  to generate a
     // suitable recipient identifier

     RecipientId recId = new RecipientId();

     recId.setSerialNumber(cert.getSerialNumber());
     recId.setIssuer(cert.getIssuerX500Principal().getEncoded());

     // handle with message
     if (!EncryptedMsg.isMimeType("application/pkcs7-mime"))
     { //非加密邮件
       throw new Exception("It is not a Encrypte message!");

     }

     SMIMEEnveloped m = new SMIMEEnveloped( (MimeMessage) EncryptedMsg);

     RecipientInformationStore recipients = m.getRecipientInfos();
     RecipientInformation recipient = recipients.get(recId);

     MimeBodyPart res = SMIMEUtil.toMimeBodyPart(recipient.getContentByToken(TokenKey.getPrivateKey(),
        TokenKey.getProvider()));



    if (res==null)
    {
    throw new NullPointerException("the mail not decypted success!");
    }

   return res;

   }

/*
public static void main(String args[])
        throws Exception
    {
       //receive mail from the pop3 host
       try
       {
       MimeBodyPart body=null;
       ReadEncryptedMail recmail=new ReadEncryptedMail();

       Message[] msg = recmail.getMail("202.38.212.1", "yhliu", "yhliu");
      System.out.println("您好，共收到"+msg.length+"封邮件");

      ProviderConfiguration pConfig = new ProviderConfiguration("Config.xml");
      //=============epass2000
      ConfigFileItem configItem = pConfig.getConfigItem(0);
      KeyStoreManager ksMgr = new KeyStoreManager(configItem, "tanglab".toCharArray());//密码

      KeyStoreCertificates storeCerts = ksMgr.getAllCertificates();
       String Certalias=null;
       for(int i=0;i<storeCerts.itemCount();i++)
       {
              if(storeCerts.getCertItem(i).hasPrivateKey())
              {
                  String alias = storeCerts.getCertItem(i).getAlias();
                  Certalias = alias;
              }
       }
       X509Certificate cert =(X509Certificate) ksMgr.getCertificate(Certalias);
       PrivateKey prikey=(PrivateKey)ksMgr.getKey(Certalias,"tanglab".toCharArray());
       //TokenPrivateKey tpk=ksMgr.getTokenKey(Certalias,null);

        // handle with message
          for (int i = 0; i <msg.length; i++)//msg.length
          {
             try
             {
               if (msg[i].isMimeType("application/pkcs7-mime"))
               {   //加密邮件
                   System.out.println("您好，这是一封加密邮件");
                //  recmail.ReadEncryptedMailAutoByToken( (MimeMessage) msg[i],"1234".toCharArray());

                // recmail.ReadEncryptedMailByToken( (MimeMessage) msg[i],tpk, cert);
                   body=recmail.ReadEncryptedMailByLocalkey((MimeMessage) msg[i],prikey,cert);
                   Object cont = body.getContent();
                   System.out.println("邮件内容如下:");
                   if (cont instanceof String)
                   {
                       System.out.println((String) cont);
                   }
                   else if (cont instanceof Multipart)
                   {
                       Multipart mp = (Multipart) cont;
                       System.out.println(recmail.handleMultipart(mp));
                   }

               }
               else
               {
                System.out.println("It is not an encrpted mail");
               }

              System.out.println("-----------------------------------------");
             }

             catch (Exception ex)
             {
               System.err.println("邮件无法解密，可能数字证书不正确！"+ex);
             }

          }

       }
       catch (Exception ex)
       {
        System.err.println("收取加密邮件发生异常："+ex);
       }

    }
*/

}